Abstract

Colonisation and late-onset sepsis due to Gram-negative bacteria in hospitalized neonates: the NeoHIEC study

Presented at the Neonatal Society 2018 Summer Meeting.

Kortsalioudaki C, Galiza E, Heath PT

1St George’s, University of London, Institute for Infection and Immunity, London, United Kingdom

Background: LOS due to GNB is an important cause of morbidity and mortality in neonates. Multi-resistant Gram-negative bacteria (MRGNB) colonisation, infections and outbreaks are of growing concern in neonatal units (NNUs) across the UK and globally. To develop strategies to control and to prevent these infections the NeoHIEC Study (13/LO/0897) was undertaken in the South-London (SL) neonatal network. It aimed to describe colonisation with GNB in hospitalised neonates and to identify possible association with bacteraemia.

Methods: Between October 2013-May 2014 peri-anal swabs were collected from neonates in 8/10 SL NNUs (2 NICU, 5 LNU, 1 SCU), stored and analysed in batches. All identified GNB were subjected to antibiotic susceptibility using the BSAC methodology. MRGNB were defined as isolates resistant to ≥3 antibiotic classes. Participating NNUs submitted details of invasive infection episodes to the neonIN (www.neonin.org.uk, 05/Q0806/34+5) database. A point prevalence survey on antibiotic-prescribing was also conducted monthly in each NNU.

Results: 1851 samples were collected from which 1341 GNB were isolated. The majority of these GNB isolates (1318,98%) were Enterobacteriaceae (Klebsiella sp (40%), E. Coli (28%), Enterobacter sp (21%)). 20% were MRGNB and 17% ESBL-positive. Overall resistance for the colonisation isolates was: co-amoxiclav (38%), gentamicin (3%), 3rd generation cephalosporins (11%), carbapenems (5%). The proportion of MGRNB in the NICUs (combined) was double that of the LNUs (combined) (22 vs 12%, p<0.001). There were 29 episodes of GNB bacteraemia with overall incidence of GNB sepsis to be 9.9/1000 NNU-admissions. E. coli was the most frequent pathogen (38%), followed by Klebsiella sp (35%). Median-age to colonisation with GNB was 28 (IQR:16-66) vs 17 (IQR:12-40) days for bacteraemia. Analysis of the antibiotic resistance data for both colonisation and invasive episodes revealed that routine screening for colonisation does not accurately predict the antibiotic resistance profile for invasive pathogens.

Conclusion: Hospitalised neonates are frequently colonised with Enterobacteriaceae. Colonisation rates with MRGNB are moderate and correlate with the NNU level of care. Routine screening for colonisation may not be a useful strategy for targeting empiric antibiotic therapy for GNB.